Extraction without Organic Solvents in the Determination of Fumonisins B1, B2, and B3 in Maize by HPLC–FLD and ELISA Tests

Abstract

The methods for the determination of fumonisins encompass several essential steps that are of great importance for obtaining accurate and reliable results. Extraction, as the first step in the sample preparation, is crucial for a satisfactory recovery. In this study, extraction methods without organic solvents were applied for the quantification of fumonisins B1 (FB1), B2 (FB2), and B3 (FB3) by high-performance liquid chromatography (HPLC) with fluorescence detector (FLD) and of total fumonisins by enzyme-linked immunosorbent assay (ELISA). The recoveries of the HPLC–FLD determination of two reference materials after extraction with distilled water were 99 ± 5.6 and 86 ± 3.9 % for FB1, and 111 ± 5 and 81 ± 1 % for FB2, while the extraction with phosphate buffer (PB) resulted in the recoveries of 104 ± 20.2 and 92 ± 8.6 %; for FB1 and 149 ± 13 and 100 ± 5.8 % for FB2. For FB3, the recovery with distilled water was 118 ± 0.5 % and with PB 131 ± 8.8 %. Two ELISA methods gave the following recoveries for total fumonisins: 100 ± 0.6 and 133 ± 0.7 % after the extraction with distilled water and 92 ± 2.2 and 123 ± 5.4 % with PB. The limits of detection and quantification using inorganic solvents and the HPLC–FLD method were at the level of micrograms per kilogram for all fumonisins, and somewhat higher than those obtained using organic extraction methods. The determination of individual and total fumonisins in the reference material by applying extraction with inorganic solvents revealed no significant difference (p > 0.05) as compared to the AOAC method and methods recommended by ELISA manufacturers. Generally, the extraction using inorganic solvents proved to be very effective for all the types of real, naturally contaminated samples.